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Query: UMLS:C0018801 (heart failure)
 72,216 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Hypocalcemia due to hypoparathyroidism (HPT) is a late complication of iron-overloaded patients with b-thalassaemia major (TM). The majority of patients have mild disease with parasthesias, while in the more severe form tetany, seizures or cardiac failure may occur. In the last 20 years we observed heart failure in 2 out of 38 (5.2%) TM patients (aged 18 and 22 years) with hypocalcemia secondary to HPT associated to iron overload. Calcium supplementation and vitamin D induced correction of hypocalcemia and resulted in an improvement of cardiac function. Calcium plays a key role in the maintenance and regulation of normal cardiac function. Extra-cellular calcium is indispensable for the contractile process since the sarcoplasmatic reticulum is unable to maintain a sufficient amount of calcium to trigger myocardial contraction. In conclusion, our observations stress the importance of a regular iron chelation therapy, adherence to treatment of endocrine complication and regular follow-up of TM patients with hypocalcemia.
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PMID:A rare cause of heart failure in iron-overload thalassaemic patients-primary hypoparathyroidism. 1840 23

Heart failure due to myocardial iron overload remains the leading cause of death in patients with transfusion-dependent anemias. Iron overload-induced cardiomyopathy is reversible if intensive chelation therapy is instituted on time. Thus, early detection of myocardial iron deposition is imperative to prevent overt heart failure. Conventional cardiac monitoring, including physical examination, electrocardiography, echocardiography or serum ferritin levels fail to predict manifest or subclinical myocardial involvement resulting from iron overload. Cardiovascular magnetic resonance imaging T2* (cMRI-T2*, pronounced T2 star) times correlate well with myocardial iron levels. This timely review focuses on the utility of cMRI-T2*, for the preclinical detection of myocardial iron overload and monitoring of myocardial iron content during chelation therapy.
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PMID:Quantification of myocardial iron overload by cardiovascular magnetic resonance imaging T2* and review of the literature. 1841 44

For patients who regularly receive blood transfusions, cardiac failure is the major cause of death. This is most alarming because it progresses rapidly and is difficult to manage. We present three pediatric patients with acute leukemia whose therapy-induced anemia was treated with different amounts of red blood cell concentrates (RCC). In all patients, a liver iron overload was measured by super-conducting interference device (SQUID) biosusceptometry and magnetic resonance imaging (MRI). MRI is a rapid, noninvasive, and widely available method of determining early myocardial iron overload caused by multiple blood transfusion due to anemia during polychemotherapy.
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PMID:Myocardial iron overload in transfusion-dependent pediatric patients with acute leukemia. 1862 23

beta-Thalassemia major is a debilitating disease with a considerable incidence in Lebanon (around 2-3% carriership). The present article describes our experience to this day with 214 patients, emphasizing the survival of beta-thalassemia major and development of complications among patients with different parameters. Fifteen deaths were reported. The most common cause of death was heart failure (60%). Patients with a ferritin level of 3,000 ng/ml showed better survival than those with a level >3,000 ng/ml (p < 0.006). In addition, patients with a ferritin level of 1,500 ng/ml showed less complication-free survival than those with a level >1,500 ng/ml (p < 0.024). High level of ferritin (1,500 ng/ml) is associated with increased risk of heart failure. Overall and complication-free survival were statistically different among patients classified according to birth cohort or ferritin level. The Chronic Care Center, a multidisciplinary center located in the suburbs of Beirut, led to an increase in complication-free as well as overall survival. Although patients are being diagnosed earlier and chelation therapy is being initiated at an earlier age, complications due to iron overload still persist. The introduction of new oral iron chelators and better iron overload quantitation methods will most likely modify this picture, and a follow-up study will examine their impact.
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PMID:Survival and complications of beta-thalassemia in Lebanon: a decade's experience of centralized care. 1900 6

Many patients with myelodysplastic syndromes (MDS) have severe anaemia. However, regular blood transfusions, which are widely used to maintain quality of life and prevent anaemia-related morbidity and mortality, have a negative impact on survival as a result of iron overload. Retrospective surveys have shown an association of transfusion dependence with hepatic, pituitary, and pancreatic dysfunction, cardiac failure, and cardiac death. Survival is significantly decreased in transfusion-dependent patients, and the main cause of non-leukaemic death is cardiac failure. However, iron chelation therapy reduces serum ferritin levels and is associated with significantly improved survival in patients with MDS. Current guidelines recommend starting iron chelation therapy after 25-50 units of blood have been transfused, or when serum ferritin levels rise above 1,000-2,000 microg/L. The patients who are most likely to benefit from iron chelation therapy are those who have low-risk disease (International Prognostic Scoring System low or intermediate-1 risk) with a life expectancy of more than 1 year. More specific studies in patients with MDS are needed to evaluate the impact of iron chelation therapy on morbidity and mortality, and provide a stronger evidence base for treatment guidelines.
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PMID:The deleterious effects of iron overload in patients with myelodysplastic syndromes. 1905 54

From 1990 to 1991, the Pediatric and Adolescent Endocrine Outpatient Clinic of Arcispedale S. Anna admitted 97 thalassaemia major (TM) patients for endocrine evaluation. Their mean age was 14.2+/-5.7 years (range 5-28 years). Sixty-eight (70%) had normal thyroid function and twenty-one (21.6%) were discharged with a diagnosis of hypothyroidism of different degrees of severity. Thirteen patients out of 21 (61.9%) were females. Twelve patients (57.1%) fulfilled the criteria for subclinical hypothyroidism (SH). Their mean age was 15.7+/-3.5 years (range 9-22 years). A positive direct correlation was observed between the following variables: TSH and serum ferritin, TG and basal TSH, basal TSH and peak levels after TRH stimulation test. In 6 out of 12 TM patients (50%) with SH type a, the basal ejection fraction assessed by MUGA scan was normal; 1 TM patient (8.3%) showed mild abnormality and 5 TM patients (41.6%) showed severe abnormalities. A normal response during exercise (increase in LVEF greater than 5 percentage units) occurred in 10 patients (83.3%). Global or segmental left ventricular dysfunction at rest and during exercise were found in 8 patients (66.6%) and 10 patients (83.3%), respectively. These cardiac abnormalities were more common in TM patients with severe iron overload and poor compliance to DFX treatment (group A: serum ferritin above 2500 ng/ml) compared to TM patients with mild-moderate iron overload (group B: serum ferritin below 2500 ng/ml). In the control group of TM patients (group C) with normal thyroid function the assessment of MUGA scan was normal in all subjects at rest and after exercise. Global or segmental left ventricular dysfunction was observed only during exercise in 50% of TM patients with normal thyroid function (group C). Our patients with SH exhibited three different thyroid function patterns during follow-up: a. 3 (25%) of 12 studied TM patients showed a normalization of serum TSH levels b. 2 patients (16.6%) showed intermittent elevation of serum TSH with normal serum FT4 concentrations c. 3 patients (25%) had a persistent mild elevation of serum TSH concentration (from 6.3 to 7.6 microU/ml) with serum FT4 concentrations within the normal range. Two TM patients (16.6%) were treated with L-thyroxine. The reason for starting therapy was an abnormality of basal LVEF in the presence of mild iron overload (serum ferritin levels 665 ng/ml and 523 ng/ml). One TM patient with persistent SH type a developed a papillary carcinoma, and another, a multinodular goiter. The serum ferritin levels at diagnosis were 4739 ng/ml and 744 ng/ml,respectively. The thyroid function in TM patients from group C remained normal during the follow-up period. Two patients (Group A: patients no. 1 and 2) with severe iron overload and poor compliance to chelation therapy died during the follow-up, due to heart failure and arrhythmia. The time intervals between the first abnormal LVEF value and the development of symptomatic heart failure were 3.8 and 4.3 years. An improvement of LVEF was observed in three TM patients from group A after 24 months of intensive subcutaneous chelation therapy with DFX, and in two patients from Group B after 12-14 months of L-thyroxine replacement therapy in association with regular iron chelation therapy. In those two TM patients the basal LVEF increased from 37% to 45% and from 45% to 49%. In conclusion, although the findings are limited to a small group of TM patients with SH type a, our results show a high prevalence of primary hypothyroidism with the predominance of its mildest form, its stable course over years in most patients, and the presence of cardiac involvement in patients with severe-moderate iron overload. Regular iron chelation therapy should be advised for these patients to prevent thyroid dysfunction and the development of clinically significant myocardial dysfunction. In addition, therapy with L-thyroxine should be considered in iron overloaded TM patients with SH and a poor response to chelation therapy and in patients with SH and mild iron overload.
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PMID:Mild subclinical hypothyroidism in thalassaemia major: prevalence, multigated radionuclide test, clinical and laboratory long-term follow-up study. 1933 74

Patients with thalassemia major have inevitably suffered from complications of the disease, due to iron overload. Among such complications, cardiomyopathy is the leading cause of morbidity and mortality (63.6% to 71%). The major causes of death in this group of patients are congestive heart failure and fatal cardiac tachyarrhythmias leading to sudden cardiac death. The free radical-mediated pathway is the principal mechanism of iron toxicity. The consequent series of events caused by iron overload lead to catastrophic cardiac effects. The authors review the electrophysiological and molecular mechanisms, pathophysiology and correlated clinical insight of heart failure and arrhythmias in iron overload thalassemic cardiomyopathy.
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PMID:Iron overload thalassemic cardiomyopathy: iron status assessment and mechanisms of mechanical and electrical disturbance due to iron toxicity. 1934 Mar 44

Congenital dyserythropoietic anemias (CDAs) are phenotypically and genotypically heterogeneous diseases. CDA type II (CDAII) is the most frequent CDA. It is characterized by ineffective erythropoiesis and by the presence of bi- and multinucleated erythroblasts in bone marrow, with nuclei of equal size and DNA content, suggesting a cytokinesis disturbance. Other features of the peripheral red blood cells are protein and lipid dysglycosylation and endoplasmic reticulum double-membrane remnants. Development of other hematopoietic lineages is normal. Individuals with CDAII show progressive splenomegaly, gallstones and iron overload potentially with liver cirrhosis or cardiac failure. Here we show that the gene encoding the secretory COPII component SEC23B is mutated in CDAII. Short hairpin RNA (shRNA)-mediated suppression of SEC23B expression recapitulates the cytokinesis defect. Knockdown of zebrafish sec23b also leads to aberrant erythrocyte development. Our results provide in vivo evidence for SEC23B selectivity in erythroid differentiation and show that SEC23A and SEC23B, although highly related paralogous secretory COPII components, are nonredundant in erythrocyte maturation.
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PMID:Mutations affecting the secretory COPII coat component SEC23B cause congenital dyserythropoietic anemia type II. 1956 5

Hereditary Hemochromatosis (HH) is an iron overload syndrome caused by increased duodenal iron absorption, which leads to excessive iron deposition in parenchymal cells of the liver and mayor organs, causing cirrhosis, diabetes, cardiac failure, endocrine complications and arthritis. There are 6 types of HH related to mutations in the genes that encode proteins of iron metabolism. HH Type I is inherited as an autosomal recessive trait of mutations in HFE gene. We investigate the prevalence of C282Y, H63D and S65C mutations in 95 individuals (77 males, 18 females) bearing iron metabolism alterations to establish an early diagnosis of HH. Among this population, 58% carried mutations in the HFE gene (45 males, 10 females). H63D mutation was found in 32.6% of the subjects (29.5% in heterozygocity, 3.15% in homozygocity). S65C mutation was only detected in the heterozygous form (5.3% of the patients), 2 of them carried also H63D mutation. C282Y in heterozygocity was found in 15.8% of the individuals; but only 4.15% carried this mutation in homozygocity. Our findings are in agreement with the prevalence of the Mediterranean origin of most of our patients, where C282Y mutation is not as common as H63D mutation.
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PMID:HFE gene mutations in patients with altered iron metabolism in Argentina. 1965 48

In b-thalassemia, myocardial iron overload contributes to heart failure, despite chelation treatment. We hypothesized that myocardial T2*, an index of iron overload, influences patients' physical activity. We assessed a thalassemic population by both cardiovascular magnetic resonance imaging (CMR) and ergospirometry test. Sixty-six thalassemic patients aged 27 (19-40) years, 30 without (NHF) and 36 with heart failure (HF), were studied. Cardiac T2* and left ventricular ejection fraction (LVEF) were evaluated using a 1.5 T system. VO(2max), AT, Mets and duration of exercise by ergospirometry were also assessed. Myocardial T2* was lower in HF compared to NHF patients (14.7 +/- 6.6 vs. 39 +/- 2 ms, P < 0.001). LVEDV and LVESV were higher in HF group compared to NHF patients (139.9 +/- 16.3 vs. 124.6 +/- 20.86 ml, P < 0.01 and 94.9 +/- 24 vs. 38.3 +/- 10.1 ml, P < 0.001, respectively). Additionally, LVEF in HF was lower compared to NHF patients (21.3 +/- 6.1% vs. 69.6 +/- 3.7, P < 0.001, respectively). All exercise parameters were lower in HF compared to NHF patients (P < 0.001). Patients within the HF group were additionally analyzed according to T2* values (<10 ms). HF patients with T2* < 10 ms (n = 13) were considered as high iron overloaded (HF-H) and the rest of them (n = 23) as (HF-L). Although LVEDV, LVESV, LVEF were similar in the two subgroups, the exercise parameters were significantly lower in the HF-H group (P < 0.001). Heart T2* correlated with all exercise parameters (P < 0.001). HF thalassemic patients have reduced exercise indexes compared to non HF. Myocardial iron overload, expressed as T2*, has a direct influence on exercise capacity, independent of LV ejection fraction and functional class.
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PMID:Effect of iron overload on exercise capacity in thalassemic patients with heart failure. 1993 25


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